phentolamine block test

The phentolamine block test (Regitin test) is carried out by the following principle: phentolamine (ie, benzyl oxazoline) is an alpha-adrenergic receptor blocker that blocks the alpha of catecholamines. - The receptor effect causes a rapid decline in persistent or paroxysmal hypertension due to elevated levels of catecholamines. Therefore, the relationship between hypertension and pheochromocytoma can be judged by the response to phentolamine. Basic Information Specialist Category: Cardiovascular Examination Category: Other Examinations Applicable gender: whether fasting: not fasting Analysis results: Below normal: Normal value: no Above normal: negative: There was no significant decrease in blood pressure 2 minutes after phentolamine injection, and there was no significant decrease in blood pressure after 7 minutes. Therefore, the test result was negative, and the clinical manifestation of pheochromocytoma was not likely. Positive: 1. The accuracy of the positive test and pheochromocytoma test is 75-100%. 2. False negative reactions are rare. The cause of false negatives may be related to secondary arteriolar lesions. Phentolamine is tested by intramuscular injection and is also prone to false negative reactions. Tips: Before the test, the patient rests in a flat position and the surrounding environment should be quiet. The sedative is stopped for at least 2 days, the antihypertensive drug is at least 3 days, and the reserpine is at least 14 days. The blood pressure is measured once every minute until the blood pressure is stable and continues to be above 22.7/14.7 kPa (170/110 mmHg) before the test can be performed. Normal value There was no significant decrease in blood pressure 2 minutes after phentolamine injection, and there was no significant decrease in blood pressure after 7 minutes. Therefore, the test result was negative, and the clinical manifestation of pheochromocytoma was not likely. Clinical significance 1. The accuracy of the positive test and pheochromocytoma test is 75-100%. 2. False negative reactions are rare. The cause of false negatives may be related to secondary arteriolar lesions. Phentolamine is tested by intramuscular injection and is also prone to false negative reactions. Abnormal result The clinical manifestations of pheochromocytoma vary widely among individuals. From asymptomatic and physical signs to sudden onset of malignant hypertension, heart failure or cerebral hemorrhage. PHEO is "about 10% rule", that is, about 10% is outside the adrenal gland, 10% is malignant, 10% is familial, 10% is in children, 10% is bilateral, and 10% is multiple. Clinical signs and symptoms are associated with excessive secretion of catecholamines, the so-called "6H performance" hypertension (hypertension), headache (headache), heart consciousness (hypertension), hypermetabolism (hypermetabolism), hyperglycemia (hyperglycemia), hyperhidrosis (hyperhidrosis) . People in need of examination: Whether the symptoms of hypertension are caused by pheochromocytoma. Positive results may be diseases: pheochromocytoma, elderly patients with acute left heart failure Taboo before inspection: 1. Stop the sedative for at least 2 days before the test, antihypertensive drugs for at least 3 days, and reserpine for at least 14 days. 2. The patient should rest in a flat position before the test, and the surrounding environment should be quiet. 3. Blood pressure is measured once every minute until the blood pressure is stable and continues to be above 22.7/14.7kpa (170/110mmHg) before the test can be carried out. Requirements for inspection: Actively cooperate with the doctor's request. Inspection process [method] 1. Stop the sedative for at least 2 days before the test, antihypertensive drugs for at least 3 days, and reserpine for at least 14 days. 2. The patient should rest in a flat position before the test, and the surrounding environment should be quiet. 3. Establish a venous channel and slowly instill saline. 4. Measure blood pressure once every minute until the blood pressure is stable and continue above 22.7/14.7kpa (170/110mmHg) before testing. 5. Slowly inject (within 1 minute) phentolamine 5 mg (1 mg from children) from the infusion tube without the patient's notice. 6. After the injection is completed, the blood pressure is measured every 30 seconds for a total of 3 minutes, and then measured every minute for 7 minutes, or until the blood pressure returns to the pre-test level. [result] 1. Normal people's blood pressure decreased 2 minutes after phentolamine injection, but the decrease did not exceed 4.67/3.33kpa (35/25mmHg). 2. In patients with pheochromocytoma, blood pressure decreased significantly after 2 minutes of injection, and the decrease was greater than 4.67/3.33 kPa (35/25 mmHg) for 3-5 minutes or longer. Not suitable for the crowd Inappropriate crowd: temporarily unknown. Adverse reactions and risks Nothing.